221646212110666 has 16 divisors (see below), whose sum is σ = 402315813579456. Its totient is φ = 89403514128576.

The previous prime is 221646212110643. The next prime is 221646212110669. The reversal of 221646212110666 is 666011212646122.

It is not an unprimeable number, because it can be changed into a prime (221646212110669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465643302516 + ... + 465643302991.

It is an arithmetic number, because the mean of its divisors is an integer number (25144738348716).

Almost surely, 2^{221646212110666} is an apocalyptic number.

221646212110666 is a deficient number, since it is larger than the sum of its proper divisors (180669601468790).

221646212110666 is a wasteful number, since it uses less digits than its factorization.

221646212110666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931286605533.

The product of its (nonzero) digits is 497664, while the sum is 46.

Adding to 221646212110666 its reverse (666011212646122), we get a palindrome (887657424756788).

The spelling of 221646212110666 in words is "two hundred twenty-one trillion, six hundred forty-six billion, two hundred twelve million, one hundred ten thousand, six hundred sixty-six".